Question: Solve for $n$ : $n - 6 = -7$
Solution: Add $6$ to both sides: $ \begin{eqnarray} \\ n - 6 &=& -7 \\ \\ {+6} && {+6} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-6 + n} &\hphantom{=}& \hphantom{-7} \\ n &=& -7 {+ 6} \\ \end{eqnarray} $ Simplify. $ n = -1$